Machine for wrapping a group of containers such as cans in material of foil type



ANDBLAD ET AL 3,48L107 Dec. 2, 1969 MACHINE FOR WRAPPING A GROUP OFCONTAINERS SUCH AS CANS IN MATERIAL OF FOIL TYPE 9 Sheets-Sheet 1 FiledJan. 11, 1967 I N VEN TORS M/ELL INGEMAR ANDBLAD lFbfi/E PAUL S/GV/WDSAMUEL SSON ERIK ERA/57' WALDEMER WETTEEEMG Dec. 2. 1969 ANDBLAD ET AL3,481,107

MACHINEFOR WRAPPING A GROUP OF CONTAINERS SUCH AS CANS IN MATERIAL OFFOIL TYPE Filed Jan. 11, 1967 9 Sheets-Sheet 5 I In" hmmgIk N AINVENTORS: I 2 KJELL INGEMAR ANOBLAD EU/VE PAUL s/am/eo S4MUELSSON ER/kE'e/vsr MLDEMAR'WETTERBEZG VERA/ER VALFR/D AM ARN IV/LS E/A/AR 00550 I@mw. W

Dec. 2. 1969 K. I. ANDBLAD ET AL 3,481,107 MACHINE FOR WRAPPING A GROUPOF CONTAINERS sUCH AS CANS IN MATERIAL OF FOIL TYPE Filed Jan. 11, 19679 Sheets-Sheet 4 er: Aim mz MM;

Dec. 2, 1969 ANDBLAD ET AL 3,481,107 MACHINE FOR WRAPPING A GROUP OFCONTAINERS SUCH AS CANS IN MATERIAL OF FOIL TYPE Filed Jan. 11, 1967 9Sheets-Sheet 5 INVENTORS: M/ELL IA/GE'MAR ANDBLAD M P L S/GWD SAMUELSSONEm 5mm" Mme-m2 EI-75255 26 yam/12 MAM-2w A/vvAmv Abram/5Q Dec. 2, 1969K. I. ANDBLAD ET AL 3,481,107 MACHINE FOR WRAPPING A GROUP OF CONTAINERSSUCH As CANS IN MATERIAL OF FOIL TYPE Filed Jan. 11, 1967 9 Sheets-Sheet6 Dec. 2, 1969 K. ANDBLAD ET AL 3,481,107 MACHINE FOR WRAPPING A GROUPOF CONTAINERS SUCH AS CANS IN MATERIAL OF FOIL TYPE 9 Sheets-Sheet '7Filed Jan. 11, 1967 I N VEN TORS: K/ELL INGEMAR ANDBL/JD RWE PAUL S/GWEDSAMUEL SSON ERIK EPA/s7 MADE/WAR perm/uses vsxe/ve/e VALFE/D A/YVA/P/VN/LS E/NAE 00550 Dec. 2. 1969 K. I. ANDBLAD- ET AL 3,481,107

MACHINE FOR WRAPPING A GROUP OF CONTAINERS SUCH AS CANSIN MATERIAL OFFOIL TYPE Filed Jan. 11, 196'? 9 Sheets-Sheet 8 INVENTORS: X/ELL MEMARwpezmia Rv/vE PAUL s/smea SAMUELSSON ERIK ms;- MLMMAR [VETTEEBEEGVERA/ER Mme/0 ANVA/PN N/LS E/A/AR opt-5o Armavsvs 1 196 9 K. I. ANDBLADET AL MACHINE'FOR WRAPPING A GROUP OF CONTAINERS SUCH AS cANs INMATERIAL OF FOIL TYPE 9 Sheets-Sheet 9 Filed Jan. 11, 1967 FIG. 23

I N VEN TORS KJELL INGEMAR ANDBLAD ROWE PAUL. SIGVARD WEI. SSON ERIK ERNT WEITERBERG VERA 7? I/ALFR/D A/VWfi V A rramvEY:

United States Patent Int. Cl. B65b 11/10, 35/36, 35/54 US. Cl. 53-159 16Claims ABSTRACT OF THE DISCLOSURE This disclosure teaches a machine forwrapping in a foil a group of containers arranged beside each other sthat viewed from above each group substantially forms a rectangle. Thecontainers are fed into the machine in a single row and are formed intogroups. Thereafter a foil casing is wrapped longitudinally over andunder the formed group and then the side openings are sealed.

The present invention relates to a machine for wrapping a group ofcontainers, such as cans, which are arranged beside each other so that,viewed from above, they mainly form a rectangle, in a material of foiltype, such as shrinkable foil, the containers then being fed into themachine in the form of one single row. It is previously known toassemble a number of cans or bottles or other containers so that theyoccupy a surface which is a module of the total surface of a loadingpallet. A group thus formed is enclosed in two sheets of shrinkable foilin such a way that the group is placed on one of the sheets and theother sheet is placed on top of the group. Adjacent edges of the twofoils are fastened to each other by means of welding. The wrapped groupis thereafter subjected to heat, and the wrapped group forms a rigidpack. This pack can thereafter quite simply be placed on a loadingpallet without any risk that the wrapping will break. A number of packsprepared in this way can thus be placed on a loading pallet, in severallayers, just as if each pack had been a carton. It is an extremelysimple and cheap method of wrapping and transporting containers.Hitherto, wrapping of containers in material of foil type has beencarried out manually, which is extremely time-consuming and expensive,owing to high wages, but in spite of this, it is cheaper than otherpacking methods.

The purpose of the present invention is to create a machine that,without any manual influence, achieves the wrapping of said groups in amaterial of foil type. The machine according to the invention isdesigned for plastic 'shrinkable foil, but it should be obvious that itcan also be used for foil of other materials, such as e.g. aluminium,paper and the like. The parts that will be varied are the members whichjoin the adjacent edges of the foil together.

The present invention is characterized by a number of different units,which carry out different operations. In the present case, these unitscomprise the parts of a complete machine, but can also compriseindependent units, which can be used in other, future machines. Theunits comprised in the machine are thus not limited to the presentmachine.

The machine according to the present invention is characterized by adividing unit for dividing said single row of containers into two rows,of a group-forming unit for forming said groups of containers comingfrom said two rows, of a blocking unit to prevent the feeding of aformed group, by a foil unit containing two rolls of foil locatedtransversely in relation to the conveyor track along which each groupformed is to be fed, one of the rolls then being located over theconveyor track and the other under the conveyor track, and the free endsof the two foils then being joined to each other through a transversalopening in the conveyor track, by a conveyor unit which transports thegroup formed past said transversal opening, by a first welding unit formaking a transversal weld joining adjacent foil surfaces at the rear endof a formed group, of a tensioning unit, which stretches adjacent foilsurfaces along the sides of the group, by a second welding unit whichwelds the last-mentioned foil surfaces, possibly a second conveyor unitwhich transports said group to or adjacent to said second welding unitand possibly by a shrinking unit in which the foils are subjected toheat of such a temperature that the foils, if they consist of shrinkableplastic, are shrunk.

The present invention will be described in more detail in conjunctionwith the attached drawings, showing the various part units of themachine. Thus, FIG. 1 shows a side view of a dividing unit, FIG. 2 a topview of same dividing unit, FIG. 3 a side view of a group-forming unit,FIG. 4 a top view of same unit, FIG. 5 and FIG. 6 a blocking unit in twodifferent working phases, FIGS. 7 and 8 a foil unit and a conveyor unitin two different working phases, FIGS. 9 and 10 a second conveyor unitin two different working phases, FIG. 11 a first welding unit, FIG. 12 atensioning unit, FIG. 13 a blower device for putting adjacent edges ofthe foil into contact with each other, FIG. 14 a second welding unit,FIG. 15 a shrinking unit, FIG. 16 another embodiment of a group-formingunit, FIG. 17 another working phase of said group-forming unit, FIG. 18another embodiment of the first conveyor unit, FIG. 19 a part of saidconveyor unit, FIGS. 20, 21 and 22 another embodiment of the tensioningunit in different working phases, FIGS. 23, 24 and 2S dilferent workingphases of a part of the tensioning unit.

FIGS. 1 to 15 show different units belonging to one and the samemachine. FIG. 1 shows a conveyor track 1 for containers 2 which, in thepresent case, have a cylindrical form. It should be obvious that thecontainers can consist of bottles, glass jars and other containers ofany arbitrary material. The conveyor track 1 can consist of an endlessbelt, and coacts with two vertical walls 3 and 4, so that the containersare guided transversely. These two walls are usually at a distance fromeach other that corresponds approximately to the diameter of a container2, and then at the part of the conveyor track which is to the left ofthe section shown in the figures. In these the distance is greater thanthe diameter of a container 2 and then preferably 1 /2 times thediameter of a container. At one side of the conveyor track a wheel 5 isarranged, which is fastened to a shaft 6, which wheel is given arotation in the direction indicated by the arrows 7 and 8. The wheel isprovided with a number of peripheral recesses 9. Each recess has a widthalong the periphery corresponding approximately to the diameter of acontainer 2 and a depth corresponding approximately to one-half of thediameter of the container. Between each recess there is a peripheraledge 10 on the wheel 5, which has a length corresponding approximatelyto the diameter of a container 2. Just before the wheel, to the left ofsame, as shown in FIG. 2, an extra wall 11 is arranged, which pressesthe containers 2 against the wall 3. This involves that when theconveyor belt 1 is moved in the direction indicated by the arrow 12, thecontainers will move towards the wheel 5, and every other container willthen come into contact with the edge and every other container with therecess 9. The container which comes into contact with the edge 10 willassume a position near the wall 4, while the container which comes intocontact with the recess 9 will come into contact with the wall 3, as isclearly shown in the part of FIG. 2 which is located immediately to theleft of the wheel 5. A little farther to the right, the distance betweenthe Walls 3 and 4 is increased so that the distance between the wallswill be somewhat greater than twice the diameter of a container. In themiddle between the two walls a wall 13 is arranged. At the left end ofthe wall 13 a rotatable wheel is arranged. This wheel is rotatablearound a vertical axle. As will be clearly noted from FIG. 2, everyother container will be fed to the conveyor track which is limited bythe walls 4 and 13, and the intermediate containers to the conveyortrack which is limited by the walls 3 and 13. The function of the wheel14 is to reduce the contact friction between a container and the wall 13at its left end. The wheel could be eliminated without any majordisadvantages, but it is an advantage to have it. The reason for the useof the wheel 5 is that, through the use of same, it is avoided thatcontainers which have been fed in will become locked together at thetransfer to the two different conveyor tracks, which can occur atintermittent operation of the conveyor belt 1. The containers from thetwo conveyor tracks are fed to a group-forming unit.

FIGS. 3 and 4 show a group-forming unit, and then only one half of sucha unit. The other half functions identically, and has been left out inorder to give a more clear picture. In the figure, the conveyor trackformed by the walls 3 and 13 will be noted to the left. The conveyortrack emerges towards a wheel 15a which is rotatable around an axle 15.If desired, the axle can be connected to a driving member, which makesthe axle turn in the direction indicated by the arrow 16. Normally, saiddriving is not required, owing to the fact that at the mouth of thelast-mentioned channel the containers are driven out on an endlessconveyor belt 17, which passes by an idler 18. The wheel 15a is providedwith a number of groups of recesses, which groups are arranged aftereach other along the periphery of the wheel. Each group has threedifferent recesses 19, and 21, which are identical for each group andhave different depths. The number of recesses corresponds to the numberof compartments 22, 23 and 24 to which the containers are to be fed. Ifmore than three compartments are desired, each group of recesses in thewheel 15a will amount to a number corresponding to the number ofcompartments.

Through the movement of the endless belt 17 towards the right, thecontainers coming from the conveyor track formed by the walls 3 and 13are forced into recesses 19, 20 and 21 in the wheel 15a, and areretained in said recesses during the continued rotation of the wheel,under the coaction of the wall and the movement of the conveyor belt.The different compartments 22, 23 and 24 are formed by the walls 26, 27,28 and 29. Said walls extend towards the periphery of the wheel in sucha way that containers located in recesses of the type which has beengiven the reference designation 21 go into compart ment 22, thatcontainers located in recesses of the type which has been given thereference designation 19 go into compartment 23 and that containerslocated in recesses of the type which has been given the referencedesignation 20 go into compartment 24. This is due to the fact that thefront walls in the recesses in the direction of rotation, straightagainst which the containers are pressed during a A to /2 turn, havesuch releasing angles that the containers are carried along to thecompartment desired. At the mouth of the conveyor track which is formedby the walls 3 and 13, a blocking wall is arranged, so that thecontainers can only be given the direction of movement which they haveobtained in FIG. 4. In the present machine, it is the intention that theconveyor belt 17 should travel only such a distance that three rows ofcontainers are collected in the compartments 22, 23 and 24. The furthermovement of the first row is blocked by a plate 31, belonging to ablocking device. At the blocking plate, two thin, rigid wires 32 and 33are arranged. These form an extension of the walls 27 and 28. The walls26 and 29, on the other hand, have a length corresponding mainly to thetotal length of the wall 28 and the wire 33. or the Wall 27 and the Wire32.

The blocking device with said plate 31 and said wires 32 and 33 isdescribed in more detail in FIGS. 5 and 6. In FIG. 5 the blocking plate31 is shown in its upper position, and in FIG. 6 in its lower position.Arriving containers 2 are blocked at the upper position. The distancebetween the top of the conveyor belt and the opposite, bottom of theblocking plate 31 is chosen so that the containers are not given anytipping movement. At the lower position the bottom of the blocking plate31 is more or less in contact with the conveyor belt. The edge of theblocking plate 31 which faces the containers is provided with a beveledsurface 34 so that the containers can pass the blocking plate 31. Thewires 32 and 33 have such a diameter that they will be in the spaceformed by the round sections which containers as a rule have,particularly if these are bottles or glass jars. The containers can thenbe placed in direct contact with each other transversely, in spite ofthe steering properties of the wires 32 and 33. The blocking plate 31coacts with a second plate 35. This is in order to achieve a connectinglink between the conveyor belt 17 and a following conveyor belt 36. Itis necessary to have such a bridge as there is always a space betweentwo conveyor belts. The bridge, which is formed by the plates 31 and 35,provides for an unhampered transfer of containers to the conveyor belt36. The plate 35 has a bracket-like plate at each end, at right anglesto the plate 35. In FIG. 5, one of said two bracket-like plates 37 isshown. Said second plate is rotatably supported on a horizontal axle 38,which is fastened to a fixed vertical wall element 39. The lowermost endof the bracket-like element is fastened to the other end of an arm 40,one end of which is fastened to a control member 41, which in thepresent case is of a hydraulic character, but can be of any other kindwhatsoever, on the condition that the control member can make the plate35 assume either the position shown in FIG. 5 or the position shown inFIG. 6. The control member 41 is fastened to a vertical bar 42,belonging to the blocking device. On its bottom, at each end, the plate31 is provided with an L-formed member, as is clearly shown in FIG. 5.At its right-hand end, said L- formed member is supported on an axle 44,which is fastened to the bracket-like plate 37. At the left-hand end ofthe L-formed element, one end of an arm 45 is supported through an axle46. The other end of the arm is movably supported on an axle 47 at thevertical wall element 39. It will thus be possible to raise and lowerthe blocking plate 31 by means of the link mechanism described. Itshould be obvious that any other suitable link mechanism can be used,provided that the blocking plate 31 can be moved between the positionsshown in FIGS. 5 and 6. The blocking mechanism described can be usedgenerally as a connecting member between two arbitrary conveyor belts inequipment in which two conveyor belts located one after the other areincluded.

For the further transport of a group of containers which has been formedin front of the blocking plate 31, a first conveyor unit is required.This is shown in its starting position in FIG. 3, together with thegroupforming unit. The conveyor unit is also shown in said position inFIG. 7. In FIGS. 8 and 9 the conveyor unit is shown in its other endposition. The conveyor unit is formed by the walls 26, 27, 28 and 29,shown in FIG. 4. Said walls are fastened to each other by means of atransversal bridge-like element 48, which is provided with a verticalaxle at each end, one of which, 49, is shown in FIG. 3. Each axle isjoined to a feeding member, and these are located on either side of thebelt 17. One of the feeding members, which is shown, has been given thereference designation 50. Each member is movable along a horizontal bar,which is parallel to the direction of movement of the conveyor belt 17.The feeding member 50 coacts with a bar 51. The conveyor unit is alsoprovided with a carrier, which consists of a transversal part 52,provided with three vertical tongues 53, 54 and 55. The part 52 isjoined at each end with a vertical bar each, designated 56 and 57. Thelower end of each bar is connected with a hydraulic cylinder, of whichthe one for the bar 56 is shown in FIG. 3, and in which it has beengiven the reference designation 58. Through said hydraulic cylinder,which is fixed to the feeding member, the carrier can be raised andlowered. In the raised position the containers can pass by, and in thelowered position the containers are pushed on by the carrier at amovement to the right of the feeding member 50. The righthand ends ofeach wall 26 and 29 in the conveyor unit are each fastened to a finger,59 and 60, which fingers are directed forwards. Each finger has itsleft-hand end supported on a horizontal axle, of which the one for thefinger 60 is shown in FIG. 3, and where it has been given the referencedesignation 61. All fingers are provided with spring members not shown,so that, at their normal positions, they assume the positions shown inFIG. 3. The right-hand end of each finger is provided with a transversalpart, 62 and 63, which parts are directed outwards.

The conveyor unit described functions in such a way that when the spacelimited by the carrier and the plate 31 has been filled with containers,the carrier is lowered from its uppermost position, as shown in FIG. 3,to the position shown in FIG. 7. Thereafter, with the aid of the feedingmember 50, the conveyor unit is moved to the right, to the end positionshown in FIGS. 8 and 9. Before such a movement can take place, theblocking unit must assume the functioning position shown in FIG. 6.After the conveyor unit has assumed the position shown in FIG. 8, thecarrier is again raised to the position shown in FIG. 3, and theconveyor unit is thereafter moved to its starting position, after whichthe blocking unit assumes the functioning position shown in FIG. 3. Inthis position the group-forming unit can form the following group. Theapplication of the conveyor unit is not limited to the present machine,but can have applications in any machine in which a conveyor unit of thekind described is required.

In FIG. 7 a foil unit is shown, in which a foil 64 comes from a roll offoil not shown. In the figure, also a foil 63, coming from a roll offoil located under the conveyor belt 36, is shown. The two free ends ofthe foils 64 and 65 are joined to each other by means of a weldingprocedure, which will be described in more detail in the following. Inthe figures, also two guiding members 66 and 67 for the foils are shown.In the present machine the foils are to consist of shrinkable plastic.During its movement towards the right, by means of the fingers 59 and60, the conveyor unit will grasp the blocking foil and move it towardsthe right, as is clearly shown in FIGS. 7, 8 and 9-.

The first-mentioned conveyor unit coacts with a second conveyor unit.This is shown in FIGS. 9, 10, 11 and 12. The second conveyor unitconsists of two fork-like elements 68 and 69. Each fork-like element hastwo parallel prongs, and the distance between the prongs corresponds tothe length of a group of containers. Said forks are movabletransversely, as is clearly shown in FIGS. 9 and 12. Each fork 68 and 69is provided with its shaft 70 and 71, each of which coacts with itshydraulic device 72 and 73, so that the forks are put into and out ofcontact with a group of containers. The hydraulic devices 72 and 73 areeach joined with a plate 74 and 75, which plates are movable in thelongitudinal direction of the conveyor belt 36.

The second conveyor unit functions in such a way that when the firstconveyor unit has moved a group of containers to the position shown inFIG. 9, the forks of the second conveyor unit are moved towards saidgroup, so

- that the second conveyor unit has a complete grip on the entire group.The moving of the forks towards the group is facilitated by said fingers59 and 60, as they form a space in front of the group. When the forks inthe second conveyor unit have the previously mentioned grip on thegroup, as shown in FIG. 10, the forks are located above the walls 26 and29. When the first conveyor unit returns to its starting position, thefingers 59 and 60 bend down under the prongs of the forks, owing totheir being spring loaded. At said group, the two foils 64 and 65 arecaused to meet at the rear of the group, and the two meeting foils arethen Welded together, so that the group is enclosed in a foil tube. Atthe same time, the foil tube formed is cut off from the two rolls, andthe separation from the two rolls along the weld then takes place insuch a way that the ends from the two rolls will be joined to eachother. This welding procedure, which has taken place at a first weldingunit, will be described in more detail in the following. The functioningof the welding unit has already been described, in order to make iteasier to understand the functioning of the machine. The second conveyorunit now moves the enclosed group along the direction of movement of theconveyor belt 36 to a position in front of a second welding station. Inthis position the forks move transversely outwards, as shown in FIG. 12.When this has taken place, a tensioning unit begins to function, whichcontains four stick-formed members 76,

77, 78 and 79. These stick-formed members, in turn, are joined to theparts 80, 81, 82 and 83, which coact with two control devies not shown,which are arranged at the plates 74 and 75. The stick members functionin such a way that when the forks 68 and 69 have left the group, asshown in FIG. 12, the stick-formed members are inserted in the openingsformed by the foil covering around the group at its sides. The insertiontakes place in such a way that the stick-formed members are inserted inthe centres of the opening and are thereafter given a movement in thelongitudinal direction of the group, so that the foil is stretched inthe way shown in FIG. 12. The purpose of this is to facilitate aforthcoming welding in each side joint. With the aid of the movement ofthe belt 36 in the direction indicated by the arrow 84, the group ismoved to a second welding unit, where said welding of the side jointstakes place. When the welding has been completed, the stick-formedmembers are returned to their starting positions.

In the foregoing it has been mentioned that the second conveyor unitmoves the group to a position in front of the second welding unit.However, according to another alternative, the forks can be given aretaining function only at the first welding unit. After the welding hasbeen completed, the forks are returned, at the same time as thestick-formed members begin to function. Thereafter, both the belt 36 andthe plates 74 and 75 are given a movement towards the right, to thesecond welding unit.

The first welding unit is shown in FIG. 11, and consists of twotransversal parts 85 and 86, which can move vertically in anyappropriate way whatsoever. When the parts 85 and 86 move towards eachother to make contact as shown in FIG. 11, the foil surfaces which areput into contact with each other by the parts 85 and 86 are fastenedtogether by means of heat or in some other known way, at the same timeas a transversal cut is made through the weld, so that the foils comingfrom above and below are separated from the foil parts which enclose thegroup. When the parts 85 and 86 thereafter separate from each other, thefoil parts which cover the group at its rear end are fastened together,as well as the free ends of foil coming from the two rolls not shown.

During the transport from the first welding unit to the second weldingunit, the longitudinal edges of the cover for the group are subjected toa jet of compressed air on each side of the conveyor belt. Each jet ofcompressed air comes from a nozzle. One of these nozzles is shown inFIG. 13, and has been given the reference designation 87. The functionof each jet of compressed air is to move the opposite foil surfacestowards each other, i.e. they are a complement to the stick-formedmembers.

The second welding unit consists of two longitudinal, fixed parts 88 and89, which are arranged one on each side of the conveyor belt 36, and arelocated at a height which corresponds to the height of the foil partswhich are to be fastened together. It is, of course, obvious that theheight can be chosen as desired. Each part 88 and 89 coacts with asecond part 90 and 91, which can move vertically and are in contact withthe parts 88 and 89. When a wrapped group is moved into the positionshown in FIG. 14, i.e. the position where the foil surfaces which are tobe fastened together thus are resting upon the parts 88 and 89, theparts 90 and 91 are moved into contact with the parts 88 and 89, andwelding of the opposite foil surfaces takes place in a known way, sothat the group is hermetically sealed. The parts 88, 89, 90 and 91 thuscontain elements which achieve welding. After the welding has beencarried out, the parts 90 and 91 are moved away from the parts 88 and89, after which the conveyor belt moves the wrapped group to a shrinkingunit, which is shown in FIG. 15. The shrinking unit consists of a numberof nozzles 92, 93, 94, 95 and 96, which blow air of such a temperaturethat the plastic foil which encloses the group shrinks in such a waythat the whole of the group becomes a rigid pack and, from the point ofview of handling, can be treated in the same way as a carton. In FIGS.16 and 17, a second design of a group-forming unit is shown. As will benoted from FIG. 16, the two groups of containers from the dividing unitare fed onto two conveyor tracks which are parallel to each other, andeach of which form an endless conveyor belt 97 and 98. The two conveyorbelts are on either sides of the surface 99, where a group of containersis to be formed. On the outer side of each of the conveyor belts 97 and98 there is a pushing member, of which only one is shown in FIGS. 16 and17. The pushing member consists of a transversely movable pusher 100. Itis fastened to one end of a shaft 101, the other end of which is amovable, pneumatic device. By means of this pneumatic device 102, thepusher 100 can be displaced between the position shown in FIG. 16 and aposition which can be located near the center of the surface 99. At eachend of the pusher, two rods 103 and 104 are arranged. Each of these rodsruns in the bearing devices 105 and 106, and 107 and 108, respectively.The purpose of the rods 103 and 104, with hearing devices, is to act sothat the pushing member 100 is always parallel to the longitudinal axisof the surface 99, the longitudinal axis of which is also parallel tothe feeding direction of the conveyor belts 97 and 98. At one end of thesurface 99, a pushing member 109 is arranged, and at the other end ofsaid surface a blocking member 110 is arranged. This blocking member ismost clearly shown in FIG. 18. If the last-mentioned figure is regardedagain, it will be noted that, at its ends, the pusher is fixed to twobars 111 and 112. At the rear end of each bar, a vertical plate 113 and1 14 is arranged. These two vertical bars each run in a groove 115 and116 in the surface 99. The two vertical plates 113 and 114 are connectedto a driving machinery not shown, preferably of a pneumatic type, sothat the pusher 109 can be moved back and forth in the axial plane ofthe surface 99, between the position shown in FIG. 16 and the positionshown in FIG. 18. The plates 113 and 114 each coact with a bar 117 and118. Each bar has a cleat. This cleat can be seen at the bar 117, andhas been given the reference designation 119. When the plate 113 comesinto contact with the cleat 119, the bar 117 is moved in the samedirection as the pusher 109. In the front end of each of the bars 117and 118 there is a transversely directed finger 120 and 121,respectively, arranged, which are directed inwards. At the front end ofeach finger a line 122 is fastened, which runs rearwards, parallel tothe bars 111 and 112. The line 122 runs on a wheel 123, which isrotatable around a vertical axle 124, and also around a verticallyarranged wheel 125, which is rotatable around a horizontal axle 126.These two wheels are fixed at the side of the bar 111. A weight 127 isfastened at the free end of the line 122. A corresponding line withwheel and weight is arranged at the upper side of the conveyor trackwhich is shown in FIG. 18. In this figure, also the two foils 64 and 65are shown, as well as an endless belt 127, arranged as an extension ofthe surface 99.

The group-forming unit described in FIGS. 16, 17 and 18 functions in thefollowing way. It is assumed, however, that only one of the pushingmembers is functioning, and that only one of the belts, 98, isoperating. When now the belt 98 is in motion, containers 2 are fed bymeans of this to a position, where the foremost container is in front ofthe blocking member 110. When this has taken place, the pushing memberstarts to function, and pushes on three containers, as shown in FIG. 17.The first longitudinal row is pushed in so far that three longitudinalrows can be placed side by side on the surface 99. When the firstcontainer is in position, the pusher 100 returns to the position shownin FIG. 16, after which the belt 98 starts up, and feeds three newcontainers to the same position as the foregoing containers. Thereafterthe pusher 100 functions anew. The last row of containers is pushed ontothe surface in the same way as has just been described. The belts 97 and98 also operate continuously. The first row can also be pushed in sothat it just comes onto the surface 99. It is then moved farther in onthe surface 99 by the following rows when these are pushed in. In FIG.18, the finished group being displaced is shown. The finished group isfirst in contact with the blocking unit 110, and cannot be displaced atall until the blocking device has assumed its non-blocking position. Itshould be obvious that a formed group can have a longitudinal row thatcontains more than three containers, as well as a width that exceedsthree containers. When both of the pushing members and the conveyorbelts 97 and 98 are used, the group is, of course, formed more rapidly.The non-blocking position is assumed only after the pusher 109 has comeinto contact with the group from the rear, but said position can also beassumed before said contact. When this has taken place, the plates 113and 114 have also come into contact with the corresponding cleats 119,which involves that the pusher takes along the bars 117 and 118, withtheir fingers and 121. The fingers move the blocking foil forwards, asis clearly shown in FIG. 18. The pusher 109 and the fingers 120 and 121,with the devices belonging to these, form a second variant of the firstconveyor unit. The conveyor unit moves the formed group to the positionshown in FIG. 18. During the transport, the lines 122 Will prevent thecontainers from moving transversely. In the position shown in FIG. 18,the conveyor unit leaves the formed group, and the group is sealed atits rear end in a way corresponding to the way shown in FIG. 11.Thereafter the enclosed group is transferred to the second welding unit,where the group is thus to be welded along its sides. At the secondwelding unit there is a tensioning unit, which is of a different designthan the one previously described. The tensioning unit consists of twoidentical parts, which are arranged on each side of the enclosed groupat the second Welding unit. Each part consists of two arms 128 and 129,which extend parallel to the longitudinal direction of the conveyor belt127. Each arm has one end fastened to a shaft 130 and 131, respectively.Each shaft is moreover arranged at right angles to its arm, and each isrotatably supported in a bearing member 132 and 133. On each shaft alsoa wheel or, alternatively, a sprocket, 134 and 135, is fastened. A line136 or, alternatively, a chain which has One end fastened to a springnot shown, and the other end of which is anchored, runs over the wheelsor sprockets. The other end of the line 136 is fixed to a rod 137 of ahydraulic device or, alternatively, to a pneumatic device 138, which cangive the line a movement. The two shafts 130 and 131 are arranged atsuch a distance from each other that the free ends of the two arms 128and 129 can be arranged facing each other. This is the starting positionof the arms. At the free end of the arms 128 and 129 the parts 139 and140, respectively are arranged, which are rotatable around the axles 141and 142, respectively, which are parallel to the longitudinal directionof the arms. At each part 139 and 140, a stick 143 and 144,respectively, is arranged. Each part 139 and 140 contains a spring 139aand 140a, respectively, which strives to turn the two sticks 143 and 144into a position which is parallel, and at right angles to the surface127 of the conveyor belt. However, the parts 139 and 140 are preventedfrom moving to the previously mentioned position through the influenceof a blocking member 145. (See FIGS. 23 and 25.) This blocking memberhas a blocking action only when the free ends of the arms 128 and 129have the position shown in FIG. 20, which shows the starting position ofthe arms.

The tensioning unit described functions in the following way. When aWrapped group is at the second welding unit and directly opposite thetensioning unit, the hydraulic member 138 is actuated in such a way thatthe rod 137 is drawn into the hydraulic device 138. The two arms 128 and129 are then given a movement upwards, to the position shown in FIG. 21.When the arms move up, the blocking member 145 loses its blockingeffect, which has the consequence that the sticks 143 and 145 are turnedinwards towards the conveyor track 127, so that the sticks will beparallel to the surface of the conveyor track. The second part of thetensioning unit, located on the opposite side, functions in an identicalway. The sticks at the two part units put opposite surfaces which are tobe welded together at the second Welding unit into contact with eachother, through streching from inside. When the welding has beencompleted, the arms are returned to the starting position, and thesticks then also return to their starting positions.

It should be obvious that the containers 2 in the lastmentionedembodiment can be transferred to the surface 99 in any appropriate waywhatsoever. In this embodiment, the lines 12 and the fingers 120 and 121have been replaced by two supporting rules, which are movabletransversely and parallel to the direction of movement of the belt 127.The rules have such a position along the conveyor track that, when agroup of containers is wrapped in foil, the whole group is locatedbetween the supporting rules. During the wrapping procedure, the twosupporting rules assume such a position transversely that the group canjust barely pass through. After the wrapping has been completed, therules move away from each other.

We claim:

1. A machine for wrapping in a foil a group of containers arrangedbeside each other so that viewed from above each group substantiallyforms a rectangle with the containers being fed into the machine in asingle row along a conveyor track which has an endless belt serving asits floor and which has side walls, the machine comprising incombination:

dividing means for dividing the single row of containers into two rows,

group-forming means for forming said groups of containers coming fromsaid two rows,

blocking means to prevent feeding of a formed group,

a foil unit including two rolls of the foil located transverselyrelative the conveyor track with one of the rolls located over and theother located under the conveyor track and with free ends of the twofoils joined to each other through a transverse opening in the conveyortrack,

first conveyor means which transports a formed group past saidtransverse opening,

first welding means for making a transverse weld joining adjacent foilsurfaces at the :rear end of the formed group,

tensioning means which stretches adjacent foil surfaces along the sidesof the formed group,

second welding means which welds the last-mentioned foil surfaces,

second conveyor means which transports the formed group to said secondwelding means,

the foil made of a plastic material which is shrinkable on heating,

shrinking means for subjecting the foil to heat of such a temperaturethat the foil is shrunk,

the dividing means comprising a distribution wheel rotatably arranged ona vertical axle and protruding partly into the conveyor track with thetransverse distance between side walls on one side of the wheel fromwhich the containers are fed toward the wheel corresponding to the widthof a container and at the other side of the wheel exceeding the width ofa container but less than twice the width of a container,

the distribution wheel provided along its periphery with equally spacedrecesses to accommodate containers and the spacing being chosen so thatevery other container is carried on the conveyor track by means of arecess and alternate containers by the periphery of the distributionwheel between successive recesses,

two following conveyor tracks provided on said other side of thedistribution wheel with each of said lastmentioned tracks having a widthcorresponding to a width of a container,

the ends of two adjacent walls of the following conveyor tracks forminga common edge at the input ends thereof.

2. The machine according to claim 1 with a vertical axle arranged atsaid common edge,

a second wheel rotatably arranged on said last-mentioned axle tofacilitate feeding of the containers into said following conveyortracks.

3. A machine for wrapping in a foil a group of containers arrangedbeside each other so that viewed from above each group substantiallyforms a rectangle with the containers being fed into the machine in asingle row along a conveyor track which has an endless belt serving asits floor and which has side walls, the machine comprising incombination:

dividing means for dividing the single row of containers into aplurality of rows,

group-forming means for forming said groups of containers coming fromsaid rows,

blocking means to prevent feeding of a formed group,

a foil unit including two rolls of the foil located transverselyrelative the conveyor track with one of the rolls located over and theother located under the conveyor track and with free ends of the twofoils joined to each other through a transverse opening in the conveyortrack,

first conveyor means which transports a formed group past saidtransverse opening,

first welding means for making a transverse weld joining adjacent foilsurfaces at the rear end of the formed group,

tensioning means which stretches adjacent foil surfaces along the sidesof the formed group,

a second welding means which welds the last-mentioned foil surfaces,

a second conveyor means which transports the formed group to said secondwelding means,

the foil made of a plastic material which is shrinkable on heating,

the distribution Wheel coacting with a number of compartments each ofwhich accommodates a row of containers with the number of compartmentscorresponding to the number of recesses in each group and eachcompartment having an Opening facing the periphery of the Wheel in sucha way that containers from recesses with the same depths are fed intothe same compartment.

4. The machine according to claim 3 with the compartments parallel toeach other and arranged beside each other.

5. The machine according to claim 4 with:

the blocking means comprising a transverse plate arranged across outputopenings of the compartments, the plate by means of a mechanismcontaining linkages of a parallelogram type is moveable between twovertical positions one of which coincides with the floor of thecompartments and the other located at a sufiicient height above saidfloor that feeding of containers from the compartments is blocked.

6. The machine according to claim 5 with:

the compartments defined by outer walls and at least one intermediatewall,

the plate having at least one wall-extension member which penetratesbetween compartments to form an extension of the intermediate wall.

7. The machine according to claim 3 with:

the compartments defined by outer walls and at least one intermediatewall,

the first conveyor means comprising said outer walls and a pushingmember which is moveable into each compartment.

8. The machine according to claim 7 with said outer walls each providedat its front end with a finger that can be pressed downward under springaction whereby on movement of the first conveyor means the fingers moveaway the foil in front of a formed group.

9. The machine according to claim 8 with fingers coacting with thepushing member when a formed group is fed forward and with the fingerslocated on each side thereof to move aside the foil.

10. The machine according to claim 9 with a line fastened to the end ofeach finger and urged parallel to the direction of movement of the firstconveyor means so that the two lines prevent transverse movement of aformed group.

11. The machine according to claim 1 with:

the second conveyor means comprises two fork-like members arrangedtransversely in relation to the formed group which they are to convey,

the fork-like members displaceable transversely to retain and releasethe formed group.

12. The machine according to claim 11 with a blower unit arrangedbetween the first and second welding means to put the foils which are tobe welded into contact with each other.

13. The machine according to claim 12 with:

a stretching unit arranged between the first and second welding units,

the stretching unit comprising transversely opposed parts each of whichcontains two stick members and control devices connected thereto,

the control devices operable to insert the pairs of sticks into lateralopenings of the foil casing and thereafter give the pairs of sticks sucha movement that the endless edge of each lateral opening is set in sucha position that two edge surfaces in contact with each other areobtained.

14. The machine according to claim 13 with each pair of sticks given amovement only in a vertical plane by its control device.

15. The machine according to claim 14 with:

each of the sticks in a :pair supported in one end of an arm in such away that they can turn in a plane at right angles to the longitudinalaxis of the arm,

the other end of said arm being supported so that it can turn around anaxle at right angles to the direction in which a formed group isconveyed,

the free ends of the two arms located exactly opposite each other whenthe sticks are in a vertical plane.

16. The machine according to claim 15 with a blocking member arranged ateach pair of arms whereby at their starting position the sticks areprevented from leaving their vertical plane.

References Cited UNITED STATES PATENTS 2,885,841 5/1959 Currie et al.5348 X 3,239,991 3/1966 Copping 534-.8 X

FOREIGN PATENTS 996,580 6/1965 Great Britain.

THERON E. CONDON, Primary Examiner 0 E. F. DESMOND, Assistant ExaminerU.S. Cl. X.R.

